Combustion efficiency might be generally improved in such a way that a compression, ignition and then explosion are designed to occur in a state that a physical performance is improved following a pretreatment process of fluid such as fuel oil or the like, the processes of which are called a fuel oil pretreatment process, thus enhancing fuel efficiency. Air pollution occurring owing to incomplete combustion can be significantly reduced.
A typical example of the conventional fuel saving device is shown in FIG. 1.
As shown therein, the conventional fuel saving device comprises a first case 1 with a fuel inlet 1a at one side and a hollow part 1b; 
a second case 2 with a fuel outlet 2a at one side and a hollow part 2b; 
a connection part 3 interconnecting the first case 1 and the second case 2 and with a spray hole 3a at its central portion;
a first rotation atomizing part 4 which is disposed in vicinity of the fuel inlet 1a of the first case 1 and has a spiral groove 4a along its outer circumferential surface in a longitudinal direction;
an acceleration part 5 which is in close contact with the first rotation atomizing part 4 and has a spray hole 5a at its central portion;
a second rotation atomizing part 6 which is disposed in close contact with the acceleration part 5 and has a spiral groove 6a on its circumferential surface in a longitudinal direction; and
three rotation atomizing tubes 7, 8, and 9 which are disposed at a hollow part 2b of the second case 2, respectively, and has spiral rotation protrusions 7a, 8a and 9a in their outer circumferential surfaces in a rotation direction, and three no-rotation atomizing tubes 7′, 8′ and 9′ which pass through and cover the outer surfaces of the rotation atomizing tubes 7, 8 and 9 and have straight rotation protrusions 7′a, 8′a and 9′ a on their outer circumferential surfaces in the rotation direction.
The above conventional fuel saving device is characterized in that fuel is inputted into a fuel inlet 1a of the first case 1, and flows along the spiral groove 4a through a concave groove part of the first rotation atomizing part 4 and continues to flow and then makes turbulence at the concave groove of the first rotation atomizing part 4, thus accelerating its own flow speed, and continues to flow along the spiral groove 4a. 
Here, while the fuel continues to flow along the spiral groove 4a, the first rotation part 4 rotates in an axial direction, which leads to atomizing fuel into atomized particles with the aid of the axial rotations.
The fuel which has passes through the first rotation atomizing part 4 is accelerated and sprays toward the second rotation atomizing part 6 through the spray holes 5a of the acceleration part 5 and keeps flowing along the spiral groove 6a. Here, the fuel makes turbulence at a concave groove and is reaccelerated and then flows along the spiral groove 6a and is finally guided to the spray holes 3a of a connection part 3 through the concave groove part.
The fuel which has reached the spray holes 3a of the connection part 3 is sprayed toward the hollow part 2b of the second case 2 through the spray holes 3a and collide in all directions with the disperse protrusions of the rotation atomizing tubes 7 disposed at the hollow part 2b. 
The fuel passes through the rotation atomizing tubes 7, 8, 9 and no-rotation atomizing tubes 7′, 8′, 9′ which are stacked in layers, respectively. Here, the fuel flows along the spiral rotation protrusions 7a, 8a, 9a of the rotation atomizing tubes 7, 8, 9, thus axially rotating the rotation atomizing tubes 7, 8, 9, and the fuel passes through the straight rotation protrusion 7′a, 8′a, 9′ a of the no-rotation atomizing tubes 7′, 8′ 9′ as it pushes the same upwards. The fuel is atomized again with the aid of the collisions between the axial rotation of the rotation atomizing tubes 7, 8, 9 and the straight rotation protrusions 7′a, 8′a, 9′ a of the no-rotation atomizing tubes 7′, 8′, 9′, and then is exhausted through the fuel outlet 2a of the second case 2 through the fuel through holes, so the fuel atomized into atomized particles is supplied to the engine.
A change occurs in the pressure depending on the consumption of the fuel exhausted through the fuel outlet 2a. The change in pressure, for example, results in a reduction in the consumption of fuel. As the pressure at the side of the fuel outlet 2a increases, the layer-upon-layer stacked rotation atomizing tubes 7, 8, 9 and no-rotation atomizing tubes 7′, 8′, 9′ are pushed toward the connection part 3, thus blocking the spray holes 3a and consequently interrupting the introductions of fuel. As the pressure at the side of the fuel outlet 2a decreases, they are pushed back by means of the spray pressure of the fuel, so the spray holes 3a of the connection part 3 are opened, thus supplying the fuel again.
The fuel is atomized into particles and is fully mixed with oxygen, so the perfect combustion of fuel can be obtained, which results in improving consumption efficiency.
The conventional fuel saving device has disadvantages in that when the fuel inlet of the first case and the fuel outlet of the second case are connected to the fuel supply hose connected to the side of the fuel tank and the fuel exhaust hose connected to the side of the engine, respectively, it is needed to insert the fuel inlet and the fuel outlet into the interiors of the fuel supply and exhaust hoses, respectively, and then they are tightened and secured by a clamp, the procedures of which seem to be very complicated.
In the conventional fuel saving apparatus, the inner spaces of the first case and the second case are arranged in perpendicular directions, so when the fuel flows at a high speed, the fuel collides a lot with the right angle portions, thus causing a lot of turbulences, which retards the flow speed of fluid. The continuous collisions might result in a lot of abrasions or damages.
In the conventional fuel saving apparatus, the first and second rotation atomizing parts rotate at high speeds by means of the flowing fuel in the interior of the first case. The continuous rotations consequently lead to abrasions at the inner side wall surface of the first case, and the first and second rotation atomizing parts cause a space between the inner side wall surfaces of the first case due to the abrasions, so the amount of the fuel straightly flowing without allowing the first and second atomizing parts to rotate, increases for thereby deteriorating the efficiency of atomizing.
In the conventional fuel saving device, fuel cohesive force is a key factor in terms of the fuel which is supplied from the fuel supply device(fuel tank) to the first case. The atomization efficiency of the fuel might decrease when trying to atomize the fuel following the attenuation of the cohesive force by the first and second rotation atomizing parts.
The conventional fuel saving device has disadvantages in that since liquid fuel gathers at the front side of the acceleration part (the direction that the fuel is introduced) in an upward direction, and the gaseous fuel gathers in a downward direction, and the condensed, deposited or floating substances contained in the fuel gather at in a downward direction, a differential pressure decreases, so the flowing performance of the fuel significantly decreases.
So, it is urgently needed to develop a new environmentally friendly fuel activation device which has a simple and reliable connection with the fuel supply and exhaust hoses, and the atomization force is enhanced with the aid of attenuation of cohesive force of the fuel, and the fuel does not freeze when the temperature is below zero, and collision or turbulence is suppressed when the fuel flows at a high speed, thus preventing the flowing rate of the fuel from lowering. The over consumption of the fuel is prevented, and the fuel can be saved a lot, and the exhaust of the air pollutant is minimized.
As the volume of the fuel particles supplied(sprayed) through the fuel saving apparatus decreases, the area contacting with the is increases, and the combustion time advantageously decreases; however 100% complete combustion is not performed by means of the amount of air additionally supplied.
Alternatively, there is provided an emulsified fuel which is combusted along with a fuel and a small amount of water. The emulsified fuel combustion system might be implemented in various forms; however the emulsified fuel combustion system generally is composed of a liquid fuel tank, a water tank, a combustion assistant device receiving a liquid fuel and water, thus manufacturing emulsified fuel, a storing tank storing an emulsified fuel, and a boiler receiving and combusting the emulsified fuel.
The combustion assistant device is generally formed of a case with an emulsifying chamber, and an impeller which emulsifies the fuel in such a way to stir liquid fuel and water in the emulsifying chamber.
As the impeller is operated, and the liquid fuel of the liquid fuel tank and the water of the water tank are transferred to the case, the liquid fuel and the water are emulsified during the operations of the impeller as the liquid fuel and the water pass through the emulsifying chamber, thus preparing emulsified fuel which is to be stored in the storing tank and is supplied to the combustion chamber for combustion.
As mentioned above, the conventional art has the following disadvantages.
The emulsified fuel has different emulsified states such as an addition ratio of water for the liquid fuel depending on the condition of a manufacture condition, due to which combustion states appear different in the boiler. As a measure to optimize the combustion states when combustion states are bad, there is a way increasing the supply amount of air so that emulsified fuel can have more chances of contacting with air.
The above described methods seem to improve a little combustion performances in effective ways; however the effects as obtained are not practical, and such methods do not seem to be necessary measures.
In the emulsifying methods, liquid fuels and water are emulsified by easily stirring them with impellers, which takes a lot of time to manufacture emulsified fuel. So, it is impossible to continue the manufacture of emulsified fuel, which means that the emulsified fuel cannot be instantly supplied to the boiler.
The emulsified fuel finished stands very unstable in its emulsified state, so emulsifying agents (such as surfactant or the like) is necessarily needed for stabilizing the emulsified state.